SNES MINI. RGB Amplifier Chip Mod or Standard 3 Wire Mod??

The reason is that when you use pads like you did they always get shifted back from the edge, I tried a few different methods when I made the addon board for the Dreamcast. Ultimately you need to use some elongated vias and add some drill holes to elongate the slot and these will stay at the edge, I edited your library to something that should work up to the edge and they are in the same location as your old pads.

 

Thanks for the advice Helder. I've never seen that done before.

Are the extra drill holes plated?

It's the pads on the underside of the vias that worry me though. With the PCB resting on top of the pins/pads of the IC, the via pads on the bottom of the PCB will end up very close to the adjacent pins/pads of the IC that they are resting on. Put a bit too much solder on by mistake and it could quite easily go under the PCB and bridge those vias to the adjacent pins/pads of the IC. That is the reason that I didn't use vias but maybe I made the wrong choice in hindsight.

 

You can always just add the underside of those vias to the paste layer so their covered by the laquer. The holes are just drill holes like any normal hole without any plating, I set them up overlapping so it makes a slot. Order some small test boards from oshpark.com using my version and yours to see how it works out, this is how I discovered this method and the pads like you did where met with the same results.

 

Hey guys, I've got an amp for my SFC and I'm ready to install it, but I figured while I've got my hands in its guts, I might see if I can do something to remove the slight buzz from it's audio. I've read online that simply isolating the audio from the board does this, you just need to run some wires from the audio chip directly to the AV connector.

So I was wondering:
1) Where can I get the left and right audio channels from?
2) Would sticking a capacitor on the wire to act as a filter also be a good idea?
3) Woild I need to cut the trace leading from the original audio source?

 

Thanks Helder. I'll try revising it based on your version and see how it goes. Funds are short at the moment though so I'm not sure when I will be able to make another full order. It will be a shame if I don't though because this project probably won't ever get finished otherwise.

I've never traced the audio channels before so I'm not sure where they come from exactly but if you are going to reconnect them to the Multi out anyway then there will be a 330pf cap connected to GND very close to multi out connections. You could just leave those caps on and cut the old circuit just before it gets to those caps or you could add your own caps and cut it right next to the multi out.

Are you sure the buzzing comes from the SFC, I've never really noticed it on mine. Have you tried a shielded Scart cable, maybe that would help.

Edit: Just had a quick look at my SFJr, the only console that I have open at the moment and I noticed that there is also a 10uf cap and 1kohm resistor in series. there may be more components, I don't know I didn't have time to trace it properly.

 

I'm using an official Nintendo SCART cable which tends to be properly shielded unlike 3rd party cables. The buzz appears when there's a bright image on screen, from what I've read online, this is interference coming from the mainboard itself. I figured if you could run the audio away from the mainboard, this would solve the issue, but I can't figure out where to connect the audio wires to!

BTW, I've just installed the retrorgb amp into my N64, 75ohm indeed seems to be the value to use to correct the brightness, though it would have been nice if it was built into the amp. Ah well. Looks great, though there's the issue that a lot of N64 games are a bit heavy on anti-aliasing, so there's not very many crisp pixels to see. Also installed the amp into my SFC, it also looks great! No more line! I'm not sure, but it sounds like the audio buzz might be worse after doing installing the amp.v Maybe not, I can't really remember clearly.